Knife apparatus with interchangeable blades

Abstract

Knives configured to use interchangeable blades, blades for those knives, and methods of making an using the knives and blades are disclosed. One knife includes a latch assembly that retains a blade in a slot of the latch assembly using a dual-stage locking mechanism wherein two different latches must be operated to exchange the blade in the slot. One latch is a button that translates a pin through the slot, and the other latch is a rocker lever that rotates into and out of contact with a notch, recess, or groove in the blade. The first latch controls movement of the second latch in order to help avoid inadvertent removal or dislodgement of the blade. Some blades include multiple notches or recesses so that they provide multiple points of contact that resist translation and rotation of the blade out of the slot, even when subjected to unusually-directed forces.

What is claimed is: 
     
         1 . A knife having an interchangeable blade, the knife comprising:
 a handle;   a latch assembly connected to the handle, the latch assembly comprising:
 a slot; 
 a rocker positioned in the slot, the rocker being rotatable within the slot between a first rocker position and a second rocker position, the second rocker position being rotated relative to the first rocker position; 
 a rocker locking member extending across the slot, the rocker locking member being movable between a locked position preventing rotation of the rocker between the first and second rocker positions and an unlocked position permitting rotation of the rocker between the first and second rocker positions; 
   a blade comprising:
 a proximal end positioned in the slot; 
 a back edge having a notch, the rocker being positioned in the notch when the rocker is in the first rocker position, the blade being prevented from removal from the slot when the rocker is in the first rocker position, the blade being removable from the slot when the rocker is in the second rocker position. 
   
     
     
         2 . The knife of  claim 1 , wherein the latch assembly and the blade are foldable into the handle. 
     
     
         3 . The knife of  claim 1 , wherein the rocker locking member is a button. 
     
     
         4 . The knife of  claim 1 , wherein the rocker locking member is biased to the first rocker position by a compliant member. 
     
     
         5 . The knife of  claim 1 , wherein the rocker locking member comprises a first diameter portion and a second diameter portion, the first diameter portion being aligned with the rocker in the slot when the rocker locking member is in the locked position, the second diameter portion being aligned with the rocker in the slot when the rocker locking member is in the unlocked position. 
     
     
         6 . The knife of  claim 5 , wherein the first diameter portion has a greater diameter than the second diameter portion. 
     
     
         7 . The knife of  claim 1 , wherein the rocker locking member is positioned on a thumbstud. 
     
     
         8 . The knife of  claim 1 , wherein the rocker comprises a pivot point in the slot that is positioned distal to the rocker locking member. 
     
     
         9 . The knife of  claim 1 , wherein the blade further comprises a longitudinally-extending notch and the latch assembly further comprises a retaining member in the slot, the retaining member being positioned in the longitudinally-extending notch of the blade. 
     
     
         10 . The knife of  claim 1 , wherein the blade further comprises a hook portion and the latch assembly comprises a retention plate, the hook extending around at least two sides of the retention plate. 
     
     
         11 . The knife of  claim 1 , wherein the proximal end of the blade has a trapezoidal shape and the latch assembly has a trapezoidal hollow, the trapezoidal shape being fitted into the trapezoidal hollow. 
     
     
         12 . A knife having a removable blade and dual-stage locking mechanism, the knife comprising:
 a handle;   a latch assembly connected to the handle, the latch assembly comprising a slot, a first latch, and a second latch, the first latch being translatable relative to the slot, the second latch being rotatable relative to the slot;   a blade retained in the slot, the blade being removable from the slot upon sequential actuation the first latch followed by the second latch.   
     
     
         13 . The knife of  claim 12 , wherein the first latch locks a position of the second latch. 
     
     
         14 . The knife of  claim 12 , wherein the second latch retains the blade in the slot. 
     
     
         15 . The knife of  claim 12 , wherein the first latch is a biased pin extending through the slot. 
     
     
         16 . The knife of  claim 12 , wherein the second latch is a rocker at least partially positioned in a notch in the blade. 
     
     
         17 . A method of securing an interchangeable blade to a knife handle, the method comprising:
 providing a knife, the knife having a handle, a latch assembly, and a blade, the latch assembly being connected to the handle, the latch assembly comprising a slot in which the blade is positioned, the latch assembly comprising a rocker and a rocker locking member, the rocker retaining the blade in the slot;   actuating the rocker locking member to unlock the rocker relative to the blade;   rocking the rocker away from the blade while actuating the rocker locking member;   removing the blade from the slot.   
     
     
         18 . The method of  claim 17 , wherein actuating the rocker locking member comprises pushing the rocker locking member laterally and at least partially through the slot. 
     
     
         19 . The method of  claim 17 , further comprising inserting a second blade into the slot while rocking the rocker, rotating the rocker toward the second blade while actuating the rocker locking member, and deactuating the rocker locking member to lock the rocker relative to the second blade. 
     
     
         20 . An interchangeable blade for a knife, the interchangeable blade comprising:
 a lateral face;   a belly edge;   a spine edge, the spine edge being positioned opposite the belly edge;   a first recess being recessed into the spine edge in a first direction;   a second recess being recessed into the spine edge in a second direction, the first direction being positioned non-parallel to the second direction.   
     
     
         21 . The interchangeable blade of  claim 20 , wherein the first direction extends toward the belly edge. 
     
     
         22 . The interchangeable blade of  claim 20 , further comprising a heel portion comprising a rear edge, the belly edge comprising a heel edge at the heel portion, the heel edge extending at an acute angle relative to the rear edge. 
     
     
         23 . The interchangeable blade of  claim 20 , wherein the spine edge comprises a protrusion extending at least partially around the second recess. 
     
     
         24 . The interchangeable blade of  claim 20 , wherein the second direction is parallel to a major longitudinal axis of the interchangeable blade. 
     
     
         25 . The interchangeable blade of  claim 20 , wherein the first direction is perpendicular to the second direction. 
     
     
         26 . The interchangeable blade of  claim 20 , wherein the belly edge comprises a sharpened gut hook blade.